糠醛-苯酚-甲醛共缩合树脂的制备与性能探究

Preparation and Property Investigation of Furfural-Phenol-Formaldehyde Co-Condensation Resin

为改善酚醛树脂在高温环境中耐酸性差的缺陷,对其进行改性。在以NaOH为催化剂条件下,使糠醛、苯酚和甲醛进行共同缩聚反应,制得热固性的糠醛-苯酚-甲醛树脂(FPF)。选用对甲苯磺酸为固化剂对合成的FPF进行固化,制备出FPF固化物。探究合成条件对FPF黏度、固含量和FPF固化物耐高温、耐强酸性能的影响。结果表明:当反应温度为95℃,催化剂用量为苯酚质量的6%,糠醛对甲醛的替代率为15%时,FPF黏度为1 200 mPa·s,固含量为87.7%。对FPF固化物进行热失重测试,其在快速分解阶段的最大分解速率为2.883%/min,较传统酚醛树脂(PF)分解速率降低33.1%。FPF固化物经高温强酸环境处理后质量保留率为96.56%,相较PF固化物质量保留率提高6.44%。糠醛代替部分甲醛改性酚醛树脂提高了耐强酸性和热稳定性,使改性后的酚醛树脂可以在强酸、高温环境中应用。

Phenolic resin is modified to improve its defect of poor acid resistance in high temperature environment.Under the condition of alkaline catalyst,furfural,phenol and formaldehyde were subjected to co-polycondensation reaction to produce thermosetting furfural-phenol-formaldehyde co-polymerization resin(FPF).P-toluenesulfonic acid was selected as the curing agent for curing the synthesized FPF,and the FPF curing compounds were prepared.The effects of synthesis conditions on FPF viscosity,solid content,and high-temperature and strong-acid resistance of FPF cured products were investigated.The results showed that when the reaction temperature was 95℃,the amount of catalyst was 6%of the mass of phenol,and the replacement rate of furfural to formaldehyde was 15%,the viscosity of FPF was 1200 mPa∙s,and the solid content was 87.7%.Thermal weight loss test of FPF cured material showed that its maximum decomposition rate was 2.883%/min in the rapid decomposition stage,which was 33.1%lower than the decomposition rate of conventional phenolic resin(PF).The mass retention of FPF cures treated with high temperature and strong acid environment was 96.56%,which was 6.44%higher compared to the mass retention of PF cures.Furfural as a substitute for part of the formaldehyde to modify phenolic resins has improved acid resistance and thermal stability,and the modified phenolic resins can be applied in environments with strong acids and high temperatures.